Measuring the electric field intensity can be applied in various industries, such as meteorology, aerospace, intelligent power grid, resource prospecting, industrial production, etc. Therefore, electric field sensors with low manufacturing costs and outstanding performance are desired.
Conventionally, an electric field sensor which employs a traditional mechanical structure is able to perform a three-dimensional measurement on electric field intensity. The manufacture of such a sensor has been developed and is of high accuracy. However, its bulky size makes it disadvantageous in application. In “A Small Three-Dimensional Electric Field Sensor” (Journal of Instrumentations and Meters, 2006, 27(11): 1433-1436, Xing ZHANG, et al.), as a typical example of traditional mechanical sensors, a small three-dimensional electric field sensor is disclosed, which is 5 cm×3.2 cm in size, and weights 80 g.
As the micro-manufacturing technology develops, a micro-manufacturing based micro electric field sensor has been raised. It has a small volume, and is eligible for massive production, and hence, is a potential replacement of the electric field sensor having a traditional mechanical structure. Existing micro electric field sensor is able to perform one-dimensional electric field intensity measurement, and has already got high sensitivity. In “A High Sensitivity SOI Electric field Sensor with Novel Comb-Shaped Microelectrodes” (Transducers'11, Beijing, 2011, 1034-1037, Pengfei YANG, et al.), as a typical example of such micro electric field sensors, a micro electric field sensor is disclosed, which is 5 mm×5 mm in size, and has a resolution of 40 V/m.
However, during the process of implementing the present invention, the applicant discovers that: in some cases, it is not assured that a direction of electric field intensity is vertical to a surface of sensor, because the direction of the electric field intensity is unknown. And when the direction of the electric field intensity to be measured is not vertical to the surface of the sensor, significant measurement error will arise if the conventional micro electric field sensor is used.